INJECTION DEVICE

Abstract

An injection device for injecting a solid dose formulation into a human or animal body, the injection device comprising an actuator having a cassette mounting portion; a cassette holder having a cassette storage portion; and a cassette selectively movable between the cassette storage portion and the cassette mounting portion, wherein, the cassette comprises a solid dose formulation and the actuator is receivable in the cassette holder to selectively move the cassette between the cassette storage portion and the cassette mounting portion.

Claims

1. An injection device for injecting a solid dose formulation into a human or animal body, the injection device comprising: an actuator having a cassette mounting portion; a cassette holder having a cassette storage portion; and a cassette selectively movable between the cassette storage portion of the cassette holder and the cassette mounting portion of the actuator, wherein, the cassette comprises a solid dose formulation and the actuator is receivable by the cassette holder to selectively move the cassette between the cassette storage portion and the cassette mounting portion, and the cassette mounting portion comprises a bayonet fitting for receiving the cassette and the bayonet fitting comprises a releasable locking mechanism for locking the cassette to the actuator.

2. An injection device according to claim 1, wherein the cassette storage portion comprises a plurality of releasable retaining elements for selectively retaining the cassette.

3. An injection device according to claim 2, wherein the bayonet fitting of the cassette mounting portion and the releasable retaining elements of the cassette storage portion are co-operable such that rotation of the actuator relative to the cassette holder releases the releasable retaining elements to facilitate selective movement of the cassette from the cassette storage portion to the cassette mounting portion and/or from the cassette mounting portion to the cassette storage portion.

4. An injection device according to claim 1 wherein the cassette holder comprises a cassette holder body and a cassette holder insert, the cassette holder insert being removable from the cassette holder body and defining the cassette storage portion.

5. An injection device according to claim 1 wherein the actuator is a pressure activated actuator which actuates the cassette to inject the solid dose formulation into a human or animal body when an axial force is applied to the actuator in the direction of the human or animal body.

6. An injection device according to claim 6, wherein the cassette holder is made from plastic.

7. An injection device according to claim 6, wherein the cassette holder insert is disposable and the cassette holder body is re-usable.

8. An injection device according to claim 1, wherein the actuator is re-usable.

9. An injection device according to claim 4, wherein rotation of the actuator is limited by a stop defined by either the cassette holder or the actuator.

10. An injection device according to claim 4, wherein rotation of the actuator in the cassette holder is limited to sixty degrees in any direction.

Description

[0018] Certain embodiments of the inventions are shown in the figures as described below:

[0019] FIG. 1 shows illustrative views of an injection device according to the present invention comprising an actuator assembly and a cassette holder.

[0020] FIG. 2 shows a detailed view of the cassette holder of FIG. 1.

[0021] FIG. 3 shows a detailed view of a cassette holder insert which is insertable into the cassette holder.

[0022] FIG. 4 shows a graph of the number of errors made per patient when using a prior art injection device for the first time without receiving a demonstration prior to first use.

[0023] FIG. 5 shows a graph comparing the number of errors made per patient when using the device for the first time without a demonstration prior to first use and after receiving a demonstration prior to second use.

[0024] The certain embodiments will now be described by way of reference to the figures.

[0025] Referring to FIG. 1, an actuator assembly 10 and cassette holder 20 are provided for injecting a solid dose formulation into a human or animal body.

[0026] The actuator assembly 10 comprises a body portion 12 and a cassette mounting portion 14. The body portion 12 houses a mechanism for operating the actuator. The cassette mounting portion 14 is configured to receive a cassette 34 comprising a solid dose formulation into a bayonette type fitting 16, or similar.

[0027] As shown in FIG. 2, the cassette holder 20 comprises a cassette holder body 22 which is open at one end. A cassette holder insert 24 is insertable into the open end of the cassette holder body 22. The insert 24 comprises a cassette storage portion 26 which stores the cassette 34. The cassette storage portion 26 is defined by three curved prongs 28 which are biased to urge against the cassette 34 to hold it in position. The cassette holder body 22 and insert 24 are made from plastic in one embodiment but the cassette holder 20 could also be made from metal. In one embodiment the cassette holder body 20 and insert 24 are disposable. In other embodiments only the cassette holder insert 24 is disposable.

[0028] A plurality of cassette holders can be stored in a sterile packaging such as a vacuum formed packaging with individually removable seals. Alternatively, each individual cassette holder can have its own vacuum formed packaging, for example, and each packaged cassette holder can be stored in a non-sterile container

[0029] In use, the actuator assembly 10 is axially aligned with the cassette holder 20. The cassette mounting portion 14 of the actuator assembly 10 is inserted into the cassette holder 20. The dose cassette mounting portion is co-operable with the curved prongs 28 of the insert 24 such that rotation of the actuator assembly 10 through sixty degrees in a pre-defined direction causes the actuator assembly 10 to act against curved prongs 28 and displace them relative to the cassette held therebetween. The cassette 34 is then released by the curved prongs 28 and retained by the bayonet fitting 16. The actuator assembly 10 can only be rotated through a maximum angle of approximately sixty degrees. Rotation is limited by a stop (not shown) defined on either the actuator assembly 10 or within the cassette storage portion 26.

[0030] The cassette 34 comprises a dosing end (not shown) and a mounting end 3). The mounting end 36 of the cassette 34 protrudes outwardly from the cassette holder insert 24. The mounting end 36 of the cassette 34 comprises a bayonet type fitting, or similar, which is co-operable with the bayonet type fitting 16 of the cassette mounting portion 14 of the actuator assembly 10. When the actuator assembly 10 is withdrawn from the cassette holder insert 24, the cassette 34 is retained by the bayonet fitting 16 of the actuator assembly 10.

[0031] The dosing end of the cassette 34 comprises the solid dose formulation and is exposed when the cassette 34 is retained by the actuator assembly 10.

[0032] To inject the solid dose formulation into a human or animal body, the cassette 34 is held against the skin at ninety degrees therefrom. The actuator assembly 10 is pushed downwards until an audible click can be heard. The click signifies that the actuator mechanism has operated and injected the solid dose formulation from the cassette 34 through the skin and into the human or animal body. Once the solid dose formulation has been injected, the actuator assembly 10 is withdrawn directly from the injection site.

[0033] After the solid dose formulation has been injected into a human or animal body the actuator assembly 10 is axially aligned with the cassette holder 24. The Cassette mounting portion 14 of the actuator assembly 10 is inserted into the cassette holder 20 after use. Rotation of the actuator assembly 10 through sixty degrees causes it to act against the three prongs 28 of the cassette holder insert 24. The actuator assembly 10 can only be rotated through a maximum angle of approximately sixty degrees.

[0034] Rotation is limited by a stop (not shown) defined on either the actuator assembly 10 or within the cassette storage portion 26. The three prongs 28 are resiliently biased in a position in which they hold the cassette 34 in place. The three prongs 28 are displaced by application of a compressive or torsional force to enable the cassette to enter or exit a space defined between the prongs 28. Once the cassette 34 has entered the space between the prongs 28, the prongs 28 revert to their unstressed configuration and retain the cassette 34. The dosing end of the cassette is orientated away from the open end of the cassette holder body 22. The cassette holder 20 and/or cassette holder insert 24 is then discarded in a safe manner.

[0035] Injection devices were tested to evaluate handling of cassettes by users. The following table sets out the sample data set used for the evaluation:

TABLE-US-00001 TABLE 1 Predominant Primary Insertion # Age Hand Known Dexterity Issues Site 1 40 Right Received physio for Upper Thigh shoulder - 90% recovered 2 40 Right None Abdomen 3 45 Left None Abdomen 4 51 Right None Upper Thigh 5 42 Left None Upper Thigh 6 47 Right None Abdomen 7 60 Left None Abdomen 8 42 Left - ambi None Upper Thigh 9 63 Right None Upper Thigh 10 59 Left Visible deformity to Abdomen hands - not diagnosed 11 53 Right Swollen index finger - Abdomen limited movement 12 55 Left Locked wrist - limited grip, Upper Thigh left arm/hand weaker 13 65 Right None Upper Thigh 14 65 Right None Abdomen 15 57 Right None Abdomen 16 45 Right None Upper Thigh 17 55 Right None Upper Thigh 18 64 Right Arthritis in fingers Abdomen 19 54 Right Arthritis Abdomen 20 64 Right Op on elbow - affects grip Upper Thigh over long periods of time 21 64 Right Osteo-athritis Upper Thigh 22 63 right Right wrist locks up Abdomen

[0036] For each patient, age, predominant hand, known dexterity issues and primary injection site were recorded. Each patient was asked to use an injection device following instructions provided with the device and the number of errors made by each patient in using the device were recorded (as summarised in FIG. 4).

[0037] The majority of errors occurred when the user handled the cassette. Each user was then given a demonstration on how to use the device and the errors made were compared with the first use trial (as summarised in FIG. 5). The number of errors observed in the repeat use trial dropped 77.5% in comparison to the first use trial. The evaluation thus indicated that there was a clear issue of patients using injection devices in an incorrect manner when left to follow the instructions provided with the injection device.